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UUID Generator

Developer Tools

Batch UUID v4 generation with multiple formats

Quick Answer

UUID Generator: Batch UUID v4 generation with multiple formats. 128-bit, format 8-4-4-4-12 hex; 122 random bits.

UUID versions

VersionHow it works
v1Timestamp + MAC, may leak device info
v3/v5Namespace + MD5/SHA-1, deterministic
v4 ←Fully random (this tool), 122-bit entropy
v7Time-ordered + random, DB index friendly
Collision chance of random v4 UUIDs: generating 1 billion per second, you would need ~85 years for a 50% collision probability (birthday bound at ~2.71×10^18 IDs). For database primary keys consider v7 (time-ordered) — random v4 scatters B-tree inserts and fragments indexes at scale.

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How to Use

  1. Paste or type content: drop code/text into the UUID Generator or fill the parameters.
  2. Choose mode/options: switch format, rules or processing as needed.
  3. Live output: results appear instantly — nothing is submitted, data stays in your browser.
  4. One-click copy: copy the output straight into your development environment.

Key Points

  • UUID Generator is a free online developer tool — open and use, no sign-up.
  • All calculations run locally in your browser; your data never leaves the device.
  • Key capability: Batch UUID v4 generation with multiple formats.
  • Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

UUID v4 (RFC 4122)

128-bit, format 8-4-4-4-12 hex; 122 random bits
Version digit fixed at 4; variant digit ∈ {8,9,a,b}
Collision: ~50% chance only after 2.71×10¹⁸ UUIDs

FAQ

How do I use the UUID Generator?
Open the page and fill in the input fields — results update automatically. Batch UUID v4 generation with multiple formats.
Are the results accurate?
Yes. Standard formulas and conversion factors are used and verified.
Is it free? Do I need to sign up?
Completely free. No registration, login or download required.
Does it work on mobile?
Yes. The responsive design works on phones, tablets and desktops.
Is my data saved?
No. Everything runs locally in your browser.

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Source & Updates

Based on RFC 4648, ECMA-262 and related specifications. Last updated: 2025-07

Authoritative sources:

Last updated:

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Maintained and periodically reviewed by the YiJianSuan editorial team — review process in ourEditorial Policy.

Cite this page: YiJianSuan. UUID Generator[EB/OL]. https://www.yijiansuan.com/en/c/dev/uuid

Results provided by this tool are for reference only and do not constitute professional advice.